This description relates to vehicle wheels, and, more particularly, to a method and apparatus for reducing air turbulence proximate the spokes of a vehicle wheel.
Controlling airflow around the wheels of a vehicle may be a way to increase the vehicle's overall efficiency and fuel economy. For example, fixed (i.e., always closed) covers or shields are available that increase the aerodynamics of a vehicle's wheels. However, such covers are considered by some to be visually less appealing than less efficient wheel designs. Also, because the covers are fixed, they may reduce the airflow to the brakes and other components behind the wheels. To provide aerodynamic wheels, without the negative aesthetics and reduced airflow, active wheel shutters have been proposed. Such active shutters require power to actuate the shutters in response to a speed of the wheel. If the power is provided by batteries, the shutter actuators may not operate properly when the batteries become weak or depleted. At least some known active shutter systems use a sensor to detect the vehicle velocity and as the velocity increases above a predetermined value, for example, 60 mph (97 km/h), the wheel-speed sensors signal a dedicated battery that powers the shutters. The shutters deploy in a fanlike pattern, closing off the openings between the wheel spokes, enabling smooth airflow across the wheels. However, there are many drawbacks to a shutter system powered by batteries and that operate according to a speed signal of the vehicle.